I plan on buying a 7 inch tablet this month. But I'm unsure about which 7-incher too choose.

My needs are only for content consumption, and I mostly use browser for that. Fire HD 7 seems to have a better battery life (over 11 hrs is stated), whereas Nexus 7 seems to have a better operating system experience (pure Android).

Or would you recommend any other tablet, such as Nook Color, Samsung Tab?

Both of them are pure android, ainol didn't change anything except some closed source drivers My bad thought you meant Ainol Fire instead of Kindle Fire >.>But I would go for the nexus 7, just because there is more development for it ^^

Not everyone has bought into Apple's closed ecosystem so to many of us nothing Apple releases matters

As for the question the OP asked, I'm still leaning towards the Nexus 7, just seems to be an all around better product that will get updates faster than Amazon's product, heck some apps in the Amazon App store are 2-3 versions behind the Play Store versions, it's frustrating the hell out of me I'm about to root and throw JB on my Fire